This invention relates to switchboard assemblies, and more specifically relates to a novel collapsible elevator structure for enabling the mounting and withdrawal of heavy circuit breakers from compartments which are above floor level. Overhead lifting devices for raising or lowering circuit breakers to a given level to enable them to be placed into or removed from vertically elevated compartments in a switchboard are well known. One particular prior art arrangement is sold by the I-T-E Imperial Corporation, of Spring House, Pennsylvania, and is described in their Bulletin 10.2-1C. The device is a traveling overhead hoist which is supported at the top of the front section of a switchboard assembly, and can move the full length of the switchboard. The overhead hoist can be operated by a hand crank operated by personnel standing in front of the switchboard and the hoist will provide the lifting power needed to raise or lower circuit breakers which have been withdrawn from vertically stacked cubicles in the switchboard.